The present invention relates generally to safety enclosures for those working slightly below ground level, and more particularly to a portable safety trench and pit form system for providing safety to workers within several feet below ground level.
The safety of workers effecting construction and repair within only several feet below ground level has become a concern with respect to collapse of the unsupported dirt and gravel pit walls. Many states, by law, now require that a pit form be used for worker safety where the pit is more than four feet deep.
Prior art, in addition to disclosing on-site fabricated wooden wall retaining structures which are difficult to reuse and, at best, deteriorate rapidly due to moisture, also disclose devices which are expensive, generally difficult to assemble and time consuming to deploy, which do not provide adequate worker protection, and/or which require additional equipment for their deployment and use such as heavy hoisting equipment or the like.
Such prior art devices with one or more of the above inadequacies are disclosed in the following U.S. Pat. Nos. 4,220,423, 840,747, 4,310,267, 3,969,852, 4,090,365, and 4,188,159.
The present invention provides a portable, lightweight pit and trench form system which includes easy to handle components and is readily assembleable by one or two workers within the excavation. The system is adapted for various size excavations and also provides work access openings through at least one side of the safety enclosure. This invention is economical to fabricate and reuseable virtually indefinitely.